1. Field of the Invention
Aspects of the invention relate generally to communication systems employing network-to-network interfaces, and more particularly to a packet-oriented cross-connect system for communication systems.
2. Description of the Prior Art
A significant portion of today's long-distance communications, such as those involving voice, multimedia, and other forms of data traffic over the Internet, are carried from a source to a destination over at least one communication “backbone,” or core network. FIG. 1 provides a simplified view of a portion of a communication network 1 employed by a first communication device 2 and a second communication device 4 for exchanging data therebetween. Each of the communication devices 2, 4 may be a personal computer, personal digital assistant (PDA), wireless phone, or any customer premise equipment (CPE) or other device capable of transmitting and receiving data.
In the particular example of FIG. 1, each of the communication devices 2, 4 is coupled to a separate access network 6, 8, respectively, by way of a user-to-network interface (UNI) 12, 14. The UNIs 12, 14 may be dial-up connections, digital subscriber line (DSL) connections, cable modem connections, or any other suitable wireline, wireless, or optical communication connection. Each of the access networks 6, 8, such as those provided by Bell South, Time Warner Cable, and others, provides end-to-end access between communication devices directly coupled to the access network 6, 8. In addition, each of the access networks 6, 8 provides communication access between a directly-coupled communication device and another remote communication device by way of a backbone or core network 10, such as SprintLink™, provided by Sprint Communications L.P. Each of the access networks 6, 8 is coupled to the core network 10 by way of a network-to-network interface (NNI) 16, 18, respectively. Since the communication devices 2, 4 of FIG. 1 are coupled to separate access networks 6, 8, data transferred between them passes through the core network 10.
Each access network 6, 8 typically provides communication access between the core network 10 and a large number of communication devices coupled directly with the access network 6, 8. Accordingly, the NNIs 16, 18 coupling the access networks 6, 8 with the core network 10 normally are high-capacity, high-bandwidth wireline or optical network connections, such as Ethernet, Packet Over SONET (POS), Asynchronous Transfer Mode (ATM), and the like. Given the extremely large amount of data usually being transferred over the NNIs 16, 18, the core network 10 typically combines, consolidates, and segregates traffic of varying formats from different access networks 6, 8 by way of a large interconnected collection of routers, switches, add-drop multiplexers (ADMs), and the like within the core network 10. This process is often called “grooming.”
This grooming of various streams or channels of data traffic potentially causes concern in at least two cases. For one, some access network customers, such as financial institutions and governmental agencies, prefer more isolated and secure data connections than those normally available through a core network 10 where extensive combining and consolidation of data channels occurs. Also, in order to troubleshoot problems exhibited by a particular communication connection, to determine service level agreement (SLA) performance, or the like, a central point of connection between channels to monitor communications with one or more access networks 6, 8 is desirable. However, such connectivity is difficult to provide in the complex and distributed grooming environment within the network core 10.